Generic pressure difference measurement transmitters for registering pressure difference between a first media pressure and a second media pressure usually comprise a sensor component and an evaluation component, wherein the sensor component comprises a pressure difference sensor, a first process connection flange and a second process connection flange; wherein the pressure difference sensor is axially clamped between the first process connection flange and the second process connection flange; wherein the sensor component is mountable at a process installation by means of the process connection flanges; wherein the pressure difference sensor is contactable by a first media pressure via the first process connection flange and by a second media pressure via the second process connection flange; wherein the pressure difference sensor has a signal output in order to output a signal, which represents a measured difference between the first media pressure and the second media pressure; wherein the evaluation component has a housing and an electronic evaluating circuit in the housing; wherein the evaluating circuit has a signal input; wherein the housing has an input opening, through which the signal output of the pressure difference sensor is connected to the signal input of the evaluating circuit; and wherein the evaluation component is held mechanically by the sensor component.
For this, the housing of the evaluation component usually has a housing neck, in which the input opening is arranged, usually screwed on a connection thread, which protrudes out from the lateral surface of a cylindrical pressure difference sensor. The construction described has proven itself. Such pressure difference measurement transmitters are available, for instance, from the assignee under the mark Deltabar and from the firm Rosemount under the designation 1151. Other embodiments of this principle are disclosed, for example, in EP 0 843 810 B1 and in the international patent application WO 96/06338.
Insofar as the pressure difference sensor is clamped between the process connection flanges, the connection thread, on which the housing neck of the housing of the evaluation component is screwed, must be completely led out from the space between the process connection flanges so that a sufficiently strongly dimensioned screw connection between the housing and the sensor component does not interfere with the flanges.
This leads to a relatively long extent of the pressure difference measurement transmitter in the direction of the axis of the connection screw thread.